Hearing aid



FIG. 1 is a front view of the hearing aid showing our new design;

FIG. 2 is a rear view thereof;

FIG. 3 is a left side view thereof, the right side view being a mirrorimage thereof;

FIG. 4 is a top plan view thereof; and,

FIG. 5 is a bottom plan view thereof.

The ornamental design for a hearing aid, as shown and described.